a. Field of the Invention
This invention relates to remote guidance systems for medical devices within a body. In particular, the instant invention relates to remote guidance systems configured for use in environments utilizing magnetic resonance imaging equipment and in other environments having a relatively high degree of electromagnetic interference.
b. Background Art
A wide variety of medical devices are inserted into the body to diagnose and treat a various medical conditions. Catheters, for example, are used for to perform a variety of tasks within human bodies and other bodies including the delivery of medicine and fluids, the removal of bodily fluids and the transport of surgical tools and instruments. In the diagnosis and treatment of atrial fibrillation, for example, catheters may be used to deliver electrodes to the heart for electrophysiological mapping of the surface of the heart and to deliver ablative energy to the surface among other tasks. Catheters are typically routed to a region of interest through the body's vascular system. In a conventional approach, an introducer is inserted through the skin surface and another introducer or sheath having an inner diameter greater than the outer diameter of the catheter is threaded through the vasculature to a region of interest. The catheter is then moved longitudinally through the sheath to the region of interest.
The introducer sheath and catheter, along with other medical devices, are typically maneuvered through the body manually by the physician while visualizing the location of the device relative to the patient's anatomy using an imaging system, such as a fluoroscopic imaging system, or a position, navigation and visualization system that determines the position of the device within the body and generates a representation of the device against an image or model of the patient's anatomy. Manual movement of medical devices within the body requires precise control and is dependent on the skill of the physician. In order to reduce or eliminate potential variability in the procedure due to physician skill and to allow performance of procedures from remote locations, remote guidance systems for medical devices have been developed using electromechanical drive systems to control movement of the devices. Several embodiments of remote control guidance systems are disclosed and illustrated in U.S. Published Patent Application No. 2010-0256558 titled “Robotic Catheter System,” U.S. Pat. No. 6,507,751 titled “Method and Apparatus Using Shaped Field of Repositionable Magnet to Guide Implant,” and U.S. Published Patent Application No. 2007-0016006 titled “Apparatus and Method for Shaped Magnetic Field Control for Catheter, Guidance, Control, and Imaging,” the entire disclosures of which are incorporated herein by reference.
Because conventional remote guidance systems rely on electromechanical drive systems to control movement of the medical device, such systems are not well suited to use in environments where there is a relatively high level of electromagnetic interference from other systems such as in a magnetic resonance imaging environment. As a result, remote guidance systems have not proven useful in such environments despite the benefits provided such systems in terms of control and ease of use.
The inventor herein has recognized a need for a remote guidance system for a medical device within a body that will minimize and/or eliminate one or more of the above-identified deficiencies.